Resistance welding machine



Sept.` 18, 1945. E J, P, JAMES 2,384,923

RESISTANCE WELDING -MAcHINE Filed .my 15, 1942 :s sheets-sheet 1 sept 13 1945 E. J. P. JAMES 2,384,923

RESI STANCE WELDING MACHINE Filed July 15, 1942 3 Sheets-Sheet 2 SM Myisla- E N I "n m S EM Mm AT. .,w .E P W w .N En S I S. E R.

` Sept. 18, 194,5.

Filed July 15, 1942 3 Sheets-Sheet 3 Patented Sept. 18', 1945 2,384,923 RESISTANCE WELDING MACHINE Edmond J. P. James, Akron, Ohio, assignor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application July 15, 1942, Serial No. 450,951

(Cl. B19- 4) 6 Claims.

This invention relates to welding machines and more particularly to resistance welding ma? chines.

An object of the invention is to provide a system for controlling the temperature of metal work pieces for a welding operation to prevent stressing.

Another object of the invention is to provide a machine for resistance seam or chain welding work pieces by means of rotated electrodes in which provision is made for creating a predetermined temperature of the work pieces prior to and after the welding operation so that the work pieces will be preheated and annealed to prevent temperature changes that would otherwise result in cracking of the metal when high carbon steel is used or when there is considerable critical temperature variance.

Other objects of the invention will appear from the following descriptiontaken in connection with the drawings, which form a part of this specification, in which:

Fig. 1 is,a perspective view of a welding machine, partly broken away. incorporating the invention;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 6.

Fig. 3 is a sectional perspective view of the upper portion of the machine showing the roller electrode and the electrode driving mechanism.

Fig. 4 is a plan view of an engine cylinder structure welded together by the machine shown in Fig. 1;

Fig. 5' is a sectional perspective view of the driven electrode having the work pieces applied thereto and showing the thermocouple for the driven electrode;

standard and has a leg 22 attached to the rear face of plate I8.

A driven work holding electrode structure is supported on platform I5. A supporting carrier 23 having a journal bearing 24 is suitably secured onthe platform, see Fig. 5, and through the bearing extends a sleeve shaft 25 on the end of which is splined a gear 26. On the forward -pro- Fig. 6 is a perspective view of the driven electrode, cylinder and holding mechanism.

Fig. 7 is a schematic diagram of the control. Referring to the drawings by characters of ref- I erence, the welding machine frame Ill includes .secure the platform and plate to the standard.

A transformer secondary 2i is arranged in housing l at the rear of the opening in the front jecting end of the shaft is a radial flange 2l and a thrust bearing 23 is arranged between this flange and the forward end of bearing 24.

The welding machine is designed to join a pair of sleeve-like work pieces which can be an engine cylinder barrel 32 and a sheet metal water jacket 33. The peripheral surfaces to be joined are shown out-of-round and are elliptical in form. The cylinder has radially projecting'.

flanges 34 and E having ellipt1cal peripheries similar to and over which the preformed elliptical jacket can be telescoped by endwise application. Flange 35 is part of a head wall 36 having fuel inlet and exhaust outlet ports 31 extending therethrough. It is proposed to form the barrel and head as castings or forgings that are welded together prior to application of the jacket, and the jacket can be formed of high carbon steel, such as stainless steel. The abutting surfaces of the anges and the jacket are welded together circularly to seal a water space between the anges. The work pieces are Joined by seam or chain welding of the resistance type in which current passes through the work pieces and the electrodes during pressure application.

The forward end of shaft 25 is arranged to provide a pilot for adapter 29 and has bosses 30 arranged to extend into the inlet and outlet valve openings 3l inthe cylinder barrel head wall. The adapter also has radial anges 3l, oneof which is coextensive with the barrel head ange and the other of which lies adjacent flange 21 when mounted on the shaft pilot. The Cylinder barrel is supported at its skirt end by adapter means including a sleeve member 38 and a core member 39. The sleeve member has a bearing on the core member and abuts barrel flange 3i at one end and a radial iiange d on the core member at the other end. The core member projects through an opening in a carrier bar di and is supported therein by bearing 62. 'I'he end of the core projecting through the supporting bar is threaded and nut 63 is screwed thereon to hold the core in position with the bar.

Carrier arms 136 extend in opposite directions from journal bearing 2d and are parallel with the carrier bar. Cylinders 65 are fixed to arms 44 and contain pistons 48' to which rods 48 are connected. These rods lextend through arms 44 and the carrier bar and retaining nuts 41 are screwed on the `ends thereof.. The pistons are actuated by power means. such as fluid pressure, and conduits 48 are connected with the cylinders for this purpose. The pistons and rods can be actuated to act on the carrier bar. so that the adapter member 38 will press the barrel against the adjacent adapter flange 3| and in turn hold the adapter 28 in driven contact with flange 21 on shaft 25. 'I'he cylinder barrel will thus be rotated with shaft 25.

Cooperating with the carrier electrode struc- I ture for the work pieces is another roller electrode structure that serves to engage the outer work piece in line with the innermost of flanges 34 or 85, depending upon which end of the barrel is ln advance when the barrel is applied to the carrier electrode structure. 'Ihe roller electrode structure includes a peripherally knurled roller 50 mounted on a. sectional shaft 5| supported by a bearing head member 52. The electrode structure isflxed to a carrier structure 58 by bolts 58 and a current conductor member 55 is secured by the bolts 58 to the bearing head member, suitable insulation being provided between the member 55 and the carrier structure 58. Current can flow through conductor 55, bearing head member 52, shaft 5| and roller 5d.

The position of the roller relative to the Jacket is determined by the carrier structure position which is controlled by fluid pressure. rier structure is suitably mounted on guide means 56 forming part of the machine frame head i3 and an actuator rod 51 is attached to the carrier. The rod is fixed to a piston 58 in cylinder 59 and a pressure system is connected with the cylinder to regulate the vertical position of the piston and roller electrode structure. This sys, tem includes a tank 80 into which air is moved through conduit |03 from a suitable pump (not shown). Air in the tank is maintained at uniform pressure and conduits 5i connect the tank with the ends of the cylinder. Pressure relief valves 64 are interposed in conduits 6| and suitable four-way solenoid controlled valve means 228, see Fig. 1, is employed to control air flow between the tank and the cylinder through either one of the conduits 6 i When air flows into the cylinder through upper conduit 6|, the roller electrode will be enby the head bearing supporting structure sl|dable in vguide means". Shaft 18 is formed of sections connected by universal ioints so that it can flex with the vertical movement of the carrier.

Gear 28 for rotating the work pieces is driven from shaft 18 so that the rotation of the roller electrode will be synchronized with rotation of the carrier electrode on which the work pieces are mounted. Gear 88 is fixed on shaft 18 and meshes with gear 88 fixed on vertical shaft 81. Gear 88 fixed on shaft 81 drives gear 88 fixed on shaft 88 and gear 8| is fixed on shaft 88 and meshes with gear 28. Gear 28 corresponds in shape to the barrel jacket so that the surface speed of the elliptical jacket on which the roller electrode engages will be uniform during each revolution of the barrel. As the rotation of the electrodes is uniform Vand the timing of the intermittent applications of current is uniform, temperature will be regulated to produce efilcient welding. This The cary temperature control and uniform roller pressure will provide efllcient welding unobtainable with either variable electrode pressure or variable timing periods relative to surface contact speed The driving roller shaft 86 can be carried by a hanger |88 pivotally supported on bracket 90| fixed to the bearing member 52 above the hanger, and a guide bolt |82 is fixed to the hanger and projects through the bracket. Spring |08 surrounds the guide boit and urges the hanger in a direction to hold the wheel 65 in driving engagement with the roller electrode 58. This arrangement of the drive wheel with the roller electrode is provided to keep the knurled periphery of the electrode in the most desirable dressed condition.

As previously related, drive gear 26 is elliptical 40 and rotates shaft 25 mounted in a fixed journal.

gaged under predetermined pressure against the barrel jacket. As the out-of-round jacket makes a complete revolution, the roller electrode will be shifted vertically and, without pressure equalizing in the cylinder and supply means, pressure of the roller against the jacket would vary. With the relief valves and the supply tank, constant pressure of the roller against the jacket is maintained.

The knurled periphery of the roller electrode is engaged and driven by a knurled driving roller 55. This roller is driven by shaft 58 on which sprocket 51 is fixed. Chain 68, driven by sprocket 68, extends around idler sprocket 10 and sprocket 61. Sprocket 58 is fixed to shaft 1| driven by bevel gear 12. Shafts 66 and 1| and the journal for sprocket 10 are carried by suitable bearings formed as a part of or fixed to member 52. An electric motor 13 is suitably mounted in housing I4 and through suitable mechanism drives gear 15 fixed to jointed shaft 15 for driving bevel gear 11. Drive is transmitted from gear 11 to gear 12 by shaft 18 through means of gears 19 and Drive shaft 88 ls flexible and has a supporting bearing |04, adjacent gear 8|, formed with ears |05 that straddle a rib on carrier 23 and are pivotally connected thereto by pin |06. Gear 8l is held in mesh with gear 28 through flexible means in the form of a spring |01 surrounding guide bolt |08 and arranged between a flange |88 on the shaft supporting bearing and flange H0 on the carrier rib.

'I'he carrier for the cylinder barrel and sleeve constitutes one electrode structure and roller 50, shaft 5| and head 52, the other electrode structure. There is an expansible arbor iii and a tapered expander member i i2 for the arbor that constitute part of the rotatable electrode structure. This arbor is in the form of an interiorly tapered sleeve that is slit for a portion of its length and receives the tapered expander. The sleeve arbor is designed to be inserted in the cylinder barrel so that it contacts therewith between llanges 34 and 35. The core member 38 will press the expander into the arbor and expand it into contact with the cylinder barrel when the piston rods 48 are operated to act on the bar 4| to seat and hold the barrel on the adapter 28 whereby they will b e rotated by drive shaft 25. The arbor thus forms a part of the electrode for conducting heat to the barrel.

The transformer secondary 2| is xed to conductor plate I8 that is in contact with carrier 23. This plate, cylinder barrel supporting structure and arbor are formed of suitable material to conduct current from the transformer to the cylinder barrel. The transformer has a free upper leg |28 that has angular conductor elements I2I secured thereto and to the conductor member E5. These conductor elements I2I are flexible to permit vertical movement of the attached electrode structure. The shaft 5I and supporting bearing member are formed of material such that current will flow from conductor elements I2I to the roller electrode.

The control for the welding system, heating system and iiuid system for raising and lowering the roller electrode structure is shown schematically in Fig. 7. The transformer primary 200 is connected by conductor 20I with power line 202 and is connected by conductor 203 with a contactor power tube means 204. such tube means being connected by conductor 205 with power line` 206. conventional design and controls `the electrical welding circuit from the primary welding conductors, or power lines, to the transformers and is suitably mounted on control panel 201. A timer switch 208 is mounted on or adjacent the control panel and is connected with the power tube means by a pair of conductors 200. The electrical system also includes a pair of control lines or conductors 2I0 and 2II. A conductor 2I2 leads from conductor 2I0 to relay 2I3 and includes a hand operated switch 2It and a solenoid switch 2I5. The relay 2I3 is connected to control timer switch 208 and switch 2I5 is arranged to be controlled by relay 2I6. Switches 2I4 and 2l5 are ln series and both' must be closed to complete the circuit to the timer switch which controls the operation of the power tube' in the welding circuit. The apparatus for resistance welding previously described forms the subject matter of my divisional patent application Ser. No. 557,242 filed October 5, 1944.

Provision is made to preheat the cylinder barrel to a predetermined temperature prior to the welding operation and to continue such temperature for a period of time after the welding operation. A contactor power tube means of conventional design 2I1 is suitably mounted on a panel 2i8 and is connected with power line 206 by conductor 2I9. The tube is connected by a tap coniuctor 220 with the transformer primary 200 so :ha-twhen the circuit is made, a limited current flows through the transformers and electrodes to The power control tube means is of tor 20L Relay 2I6 -is controlled by the temperature of the barrel so that the heating circuit switch 225 will be opened while the welding circuit switch 2I5 is closed. The relay is connected by conductors 230 and 23| with a thermocouple 232 arranged preferably vwithin adapter 29 and in thermal contact with the end wall 36 of the cylinder b arrel. Below a predeterminedbarrel temperature relay 2 I6 causes switch 225 to be closed and switch 2I5 to be open and above such temperature switch 2 I 5 is closed and switch 225 is opened. A thermostat switch 233 can be arranged in conductor 23| to control the temperature at which the -thermocouple is effective to open and close the switches.

The electrical control, in the relation shown in Fig. 7, is ineffective to lower the roller electrode, `to heat the barrel or to perform a welding operation. After placing the barrel and jacket in proper relation to each other and on the carrier, the motor 13 can be started by a suitable switch (not shown) to cause rotation of the roller electrode.

The switch 225 is closed and the treadle 230' isdepressed sufficiently to close switch 221, but not switch 226. Solenoid valve 229 will be shifted down to admit air pressure to the top of piston 58 to thus lower the roller electrode into welding pressure engagement with the jacket. The treadle 221 is next further depressed to close switch 22S which energizes relay 222 to close switch 22I controlling the power tube between conductors 2I9 and 220 so that current will A'low through a portion of the transformer primary and conduc- This circuit energizes the electrodes causing the cylinder barrel to heat up.

When the cylinder barrel reaches a predetermined temperature, that is, suiiiciently preheated for the welding operation, the thermocouple influences relay 2 I6 to cause switch 225 to open and switch 2I5 to close. Opening switch 225 will break the heating circuit, and closingr switch 2I5 will establish the control circuit to the timer switch relay which will establish and control the welding circuit through the tube means 202 beneat the cylinder barrel when the electrodes are n welding position. The-tube means controlling ;he preheat circuit is under the control of a iwitch 22| -actuated by relay 222 which is conv iected with conductor 2II by conductor 223. A :onductor 222 connects the relay 222 with coniuctors 2I2 and 2I0 and switches 225 and 226 arranged in series. Switch 225 is connected to opfrate with switch 2I5 in response to relay 2I6 ind switch 226 is arranged to be operated -manially. In order to establish the heating circuit, t is necessary that switches 225 and 226 both are 'ksgsake of convenience, a switch 221 controls he circuit to solenoid valve 229 that regulates tir iiow to the cylinder for raising and lowering he roller electrode and is connected to be oper- .ted by the same treadle 230 that operates witch 225. Switches 226 and 221 are normally and are closed by the treadle, the arrangereerxit being such that switch 221 will be closed lpon light depression of the treadle and will reriain closed while the treadle is further depressed o close switch 226. In this manner the fluid ressure will bring the welding roller into weldrig pressure engagement with the cylinder jacket rior to and while switch 226 is closed.

tween conductors 203 and 205 so that current will flow through .conductors 203, 20| and the transformer from the welding power lines. The timer switchlis preferably of the character whereby a chain or stitch welding operation is provided.

When the cylinder barrel has made a complete revolution during the welding operation of the machine, switch Zl is opened to break the welding circuit even though the thermocouple retains the switch 2I5 closed. During the welding operation the treadle has been depressed to maintain switch 221 closed so that the roller electrode will remain pressed against the barrel jacket. If the treadle has been released sumciently to open switch 226, it is again depressed to close switch 225 and when the barrel cools down to below the before-mentioned predetermined temperature, switch 225 will close and again establish the heating circuit which will continue to maintain the barrel heated until the treadle is released to open switch 225. Further release of the treadle will open switch 221 releasing solenoid valve 229 so that it will' move upwardly allowing air flow to `the underside of piston 58 and thereby raising the roller electrode from the barciples involved are susceptible or numerous other applications which will readily occur 4to persons skilled in the art. The invention is therefore t be limited only as indicated by the scope of the appended claims.

What is claimed is:

l. in a machine having a pair ofelectrode means for resistance welding work pieces together, electric circuit means connected with the electrodes for heating the work pieces, electric circuit means for supplying welding current to said electrode means. a pair of switches in series in said welding circuit means, one of said switches being controlled manually and the other switch being normally open. a normally closed switch in the heating circuit. and means responsive to temperature rise in one of the work pieces for closing the normally open welding circuit switch and opening the normally closed heating circuit switch.

2. In a machine having a pair of electrode means for resistance welding work pieces together, means for heating the work pieces,v electric circuit means for supplying welding current to said electrode means, a pair of switches in series in said circuit means, one of said switches -belng manually controlled and the other switch being normally open, a thermocouple contacting one of the work pieces, and relay means connected with the thermocouple and actuating'said ing circuit means connected with the transformer for supplying current to the electrodes, a pair of switches in series in the heating circuit means, one of said switches being manually operated and the other switch being normally closed, and means including a thermocouple contacting a work piece escasas 4. in a machine having e, pair of electrode means for resistance welding work pieces together, a controlled circuit for supplying welding current to the electrode means including a transformer. a heating circuit means connected with the transformer and connected to supply heating current to the worls pieces through the electrode me, a pair of switches in. series in said heat ing circuit means, one of said switches being manually controllable and the other switch normally closed, a thermocouple contacting one of the work pieces, and means including a relay connected with the thermocouple and actuating said normally closed switch to open theheating circuit when the thermocouple is heated by a predetermined temperature rise in the contacted work piece.

5. In a welding machine having a pair of electrode means for resistance welding work pieces together, an electric circuit for supplying welding current to the electrode means including transformer means, a normally open control switch in the welding circuit, an electric circuit connected with the transformer for supplying a heating current to the electrode means, a normally closed control switch in said heating circuit, and means including a thermocouple controlled by a predetermined temperature of one of the work pieces for shifting. said switches to close the welding circuit and to open the heating circuit.

6. In a welding machine having a pair of elec-- trode means for resistance welding work pieces together, an electric circuit for supplying welding current .to the pair of electrode means, an

electric circuit for supplying heating current to the pair of electrode means, a dual switch normally opening thewelding circuit and closing the heating circuit, and means including a thermocouple responsive to a predetermined temperature rise invone of the work pieces for shifting the duall switch to close the welding circuit and open the heating circuit.

EDMOND J. P. JAMES. 

